1. Field of the Invention
The present invention relates to a memory system and a data reading and generating method, which can be applied, for example, to a memory system having a nonvolatile memory for storing content like game data, and to a data reading and generating method for reading data from the nonvolatile memory and generating new data from the read data.
2. Description of the Background Art
Conventionally, there are nonvolatile semiconductor memories used to store content like game data. Also, there are conventional memory systems that include such a nonvolatile semiconductor memory and a controller for reading data from the nonvolatile semiconductor memory (for example, see Japanese Patent Application Laid-Open No. 2003-162433 (hereinafter referred to as Patent Document 1)).
Also, Japanese Patent Application Laid-Open No. 2002-24090 (hereinafter referred to as Patent Document 2), for example, discloses a conventional technique related to a nonvolatile semiconductor memory. The technique of Patent Document 2 enables protection of the data contained in the nonvolatile memory.
In the techniques disclosed in Patent Documents 1 and 2, the nonvolatile semiconductor memories (hereinafter referred to simply as nonvolatile memories) store ROM code itself (hereinafter, data whose contents can be utilized for a given purpose in its intact form is referred to as ROM code).
Accordingly, the ROM code stored in the nonvolatile memory can be extracted by accessing the nonvolatile memory (that is, by observing the chip itself). Thus, the contents of the ROM code can be easily utilized, and the ROM code itself can be easily extracted, and therefore it is not possible to ensure the security of the content like game data (which can be regarded also as ROM code) when the content is stored as ROM code in the nonvolatile memory.